Will add proper way to enable it later.

Add --with-graphite2.  Defaults to off.

If there's a mark ligating forward with non-mark, they were
inheriting the GC of the mark and later get advance-zeroed.
Don't do that if there's any non-mark glyph in the ligature.

Sample test: U+1780,U+17D2,U+179F with Kh-Metal-Chrieng.ttf

Also:
Bug 58922 - Issue with mark advance zeroing in generic shaper

Seems to work...

Mozilla Bug 873902 - Display Arabic text with diacritics is bad
https://bugzilla.mozilla.org/show_bug.cgi?id=873902

Fixes previous commit's test.

Failing now.

Bug 64476 - Typo in hb_set_t.get_min()

Some infrastructures use DEBUG as a generic symbol.

This is not ideal as we don't like -L/usr/lib in our linker line.
But this is only relevant to environments that don't have pkgconfig
files for ICU...

https://github.com/behdad/harfbuzz/pull/2

Sigh..

Bug 64039 - undefined macro AM_PROG_AR

The compile() function is starting to become illegible...

We always push a pause at the end such that each lookup falls in exactly
one pause_map_t.  Now, only if I can find a better name for that...